TR4A "rear torque steer issues.

[329art]

OK guys. This thing is baffling me. Still has the butt wiggle. Is this as good as it gets on the TR4A with the deep arched springs?

Axles are rebuilt and end float is perfect.
Wheel hubs and wheels rebuilt and good.
Replaced NEW rubber bushings with Racestorations upgrade bushings and brace on spring eyes.
The distance pieces have been bushed and there is virtually no movement between the spring and axle. They are mounted correctly to the axle and torqued.
The shocks are good and working.

It is slightly better than before but I can still notice the rear end steering the car left under load and then settles back to the right off the gas.

Is this as good as it gets with the TR4A? I know the TR4 has different springs and geometry out back so that doesn't apply.

[Motorsport Mickey]

So for clarity, this is a TR4a but with a US spec “live axle” which has deep dish rear springs ?

Stuart will have worthwhile input on this, his rear leaf springs are more the almost flat spring profile on his TR4a live axle. 
My initial thought is have you checked the axle for secured position as regards attitude ? I would strap a couple of lengths (4 foot) of square 2” section and straight to the tyre as near to the centre ( depending on wheels) as possible. Project the timber backwards Parallell to the ground and with help measure the distance between the ends of the timber and another measurement taken close to the tyre. You are looking for a similar measurement, if it isn’t it sounds to me like the axle is fitted at an angle.

Mick Richards

PS: I suppose you used new nylocks to secure the axle to the U bolts ? Tighten them up to torque ( 30 lbs ft from memory) no I don’t think the nylocks will have moved, but I do know that the axle U bolts will stretch a little under subsequent tightening and relax the pinch on the axle allowing movement.

Edited November 6, 2023 by Motorsport Mickey

[329art]

Yes all of the above. I had the car on a professional alignment machine to check all of that and everything in the rear is tight. My thoughts now are that the axle tubes may be loose in the housing as both sides show some seepage of fluid there. 

[BlueTR3A-5EKT]

57 minutes ago, 329art said:

Yes all of the above. I had the car on a professional alignment machine to check all of that and everything in the rear is tight. My thoughts now are that the axle tubes may be loose in the housing as both sides show some seepage of fluid there. 

If it’s axle tubes loose I would think oil staining or leakage would be obvious at the joint where the tubes enter the hypoid casing.   Unless it has no oil in it…….

Clean and drive to check.

[329art]

I'm prepping my spare housing to be welded as we type. I think that is the issue unless other thoughts?

 

[stuart]

Have you shimmed the hubs correctly to centre the thrust button, lack of shims will mean the half shafts float in and out.

Stuart.

[BlueTR3A-5EKT]

Is this car on wire wheels?

Could it be a failing wheel?

[329art]

Hubs are shimmed correctly and wire wheels have been rebuilt by Hendrix, who is one of the best. it is a solid axle car.

[stuart]

Presumably your in the US? Whats the history of the car? Have you replaced the rear springs as there was some issue quite a few years ago with those springs being the wrong camber and consequentially the axle was sitting down hard on the chassis and so steering inputs would slide the axle slightly to one side and then foot down would slide it back but in an odd way. I fitted new ones to mine but loaded the car up till the springs were considerably flatter and then fitted spring clamps to stiffen the springs in that attitude. I also have considerably uprated lever arm shocks too. It always goes where I point it and corners really well and straight line stability is perfect so there must be something we are missing with yours.

Stuart.

 

 

Edited November 7, 2023 by stuart

[ricky30dk]

Hi Art,

I have the same issue on my live axle US-import TR4A - when I eventually get off my backside and go into the garage, I have decided to try the following one at a time and in this sequence :

1. Tighten up the U bolt nuts

2. Clamp the springs as mentioned by Stuart (and others in other threads)

3. Fit a set of uprated rear dampers

1 comes for free, 2 almost free and 3 not ridiculously expensive. 

Cheers

Richard

[rcreweread]

Rich - also check if your axle tubes are slightly loose in the diff housing - if you have any oil leakage around that joint, then that's a good indication they might not be fully tight - I think you can weld them in situ but others with more experience will know better.

Cheers Rich

[329art]

Yes, both axle tubes are seeping fluid. I have a spare axle that I am in the process of welding and rebuilding. Hopefully that will cure it. If not then I will take a good look at the springs.

Stuart: If the car is sitting on the ground and unloaded, what kind of space should there be between the axle housing and the frame? That is something I can take a look at. Also could too long of a bump stop affect the axle in this way? These pics are with the car on the lift and not on the ground.